This invention relates generally to timed control valves and the like for controlling and regulating fluid flow to multiple fluid outlets. More particularly, this invention relates to a timed control valve assembly for maintaining a regulated fluid flow through a fluid outlet for a selected time interval and then for automatically switching state to direct the fluid flow to a different fluid outlet. The invention has particular utility in a swimming pool environment for supplying filtered pool water at a predetermined minimum pressure to an automatic in-the-pool cleaning device and then, after a selected time interval, switching state to halt cleaning device operation and resume normal recirculation of filtered water to the pool.
In a conventional swimming pool water filtration system, a circulation pump and a filter unit are installed at a convenient position outside the pool. In operation, the circulation pump cycles pool water through the filter unit for removal of dirt and other suspended particulate matter, followed by recirculation of the filtered water to the swimming pool through a return conduit. To maintain proper standards of cleanliness and water clarity, the circulation pump is normally operated on a daily schedule, and moreover, must have a relatively high volumetric flow capacity sufficient to circulate and filter the entire volume of water contained in the pool in a few hours of pump operation. For example, in the state of California, swimming pool filtration standards require the circulation pump to be capable of circulating the entire volume of pool water in not more than twelve hours for residential installations and not more than eight hours for commercial installations. In actual practice, a typical daily operating time for a pool filtration system is about six to eight hours, with an electric time being frequently provided for automatically starting and stopping pump operation to prevent inadvertent excessive energy consumption.
While a swimming pool filtration system of the type described above is essential for maintaining water cleanliness and clarity, such filtration systems by themselves are incapable of maintaining a swimming pool in a satisfactory state of cleanliness. For example, conventional water filtration systems are not designed for removing sizable debris, such as leaves, or for removing particulate matter which has settled onto the pool bottom or side walls. Accordingly, periodic cleaning of the pool bottom and side walls is required for removal of such sizable debris and sediment.
A variety of in-the-pool cleaning devices are well known for use in cleaning the bottom and side wall surfaces of a swimming pool. One such device comprises, for example, a so-called vaccum head which is connected to the suction side of the pool filtration system and then moved manually over submerged pool surfaces to draw debris and sediment into the main filter unit.
In recent years, a variety of automated in-the-pool cleaning devices have become popular for removing or assisting in the removal of debris and sediment without requiring manual operation or attention. See, by way of example, the in-the-pool cleaning devices shown and described in U.S. Pat. Nos. 3,032,044 and 3,822,754. Such automated in-the-pool cleaning devices in general are driven by a supply of pressurized water.
One readily available source of pressurized water for powering an in-the-pool cleaning device comprises the pool water filtration system. However, connection of the filtration system return conduit to the in-the-pool cleaning device results in a substantial and undesirable backpressuring of the pool circulation pump to increase pump load and decrease the pump flow rate thereby increasing pump energy consumption and prolonging the time period the pump must be operated to maintain water cleanliness. In an effort to overcome these disadvantages, the use of booster pumps has been proposed for boosting the pressure of a portion of the filtered water discharged by the circulation pump without significantly increasing circulation pump backpressure, with the pressure-boosted water being supplied to the in-the-pool cleaning device at a pressure sufficient for cleaning device operation. However, the provision of a second pump in the filtration system also undesirably increases energy consumption and further substantially increases the cost of pool cleaning equipment.
Additional problems which have been encountered with automated in-the-pool cleaning devices relate to a lack of satisfactory timing mechanisms for limiting their time interval of operation to correspondingly limit overall cleaner wear and power consumption. Manual on-off operation of the cleaning device, of course, undesirably requires operator attention and is subject to operator forgetfulness. Automatic timing devices heretofore available have not been integrated satisfactorily with the timed operation of the main circulation pump, thereby permitting unintended failure of the cleaning device to operate according to schedule.
There exists, therefore, a significant need for an automated valve apparatus having integrated timing means for activating and operating an in-the-pool cleaner device in conjunction with a conventional pool filtration system and in an energy-efficient manner, and for automatically halting cleaner device operation at the conclusion of a predetermined time interval. The present invention fulfills this need and provides further related advantages.